This invention relates to a multi-compartment refrigerator divided into a freezer and fresh food compartment, each having front door openings and more particular to a system for minimizing the formation of condensation around the openings where heat leakage reduces exterior temperatures slightly below ambient.
In many prior art attempts at controlling condensation, a portion of the refrigeration system liquid line has been employed around the cabinet door openings such as U.S. Pat. Nos. 2,135,091-Newill; 3,572,051-Benasutti; and 3,984,223-Whistler, Jr. In applying the approach as a means for controlling condensation, the liquid line is transferred to the cabinet whenever the refrigeration system is operating. This practice is not efficient in that heat is needed only when the ambient humidity is so high that the reduced cabinet temperatures around the door openings are below the dew point, causing moisture to condense on these surfaces. The constant application of heat causes some of the heat from the liquid line to be transferred into the compartments and, accordingly, the refrigeration system must run for longer periods of time to overcome this heat source. In other prior art attempts, electric heaters are employed which consume a relatively large amount of energy. To improve the efficiency of these electric heaters, switches have been employed which allow the user of the apparatus to manually de-energize the heaters when desired, such as under low ambient humidity conditions. Other attempts at improving efficiency of electric heaters are taught in U.S. Pat. Nos. 3,859,502-Heaney and 3,939,666-Bashark in that energization of the heaters is automatically controlled. In any instance, the employment of heaters for controlling condensation requires additional use of energy independent of the refrigeration system.